Sex Disparities in Outcomes of Early Stage Colorectal Cancer: A Population-Based Study.

BACKGROUND: Women have been shown to experience longer overall survival after colorectal cancer (CRC) diagnosis than men even after adjusting for disease stage and management. However, the etiology of this observation is not well understood, and the impact of non-CRC health conditions on survival has not been described. We aimed to evaluate the prognostic role of sex on CRC-specific outcomes.

PATIENTS AND METHODS: All patients who underwent primary resection of stage I to III CRC from 2001 to 2005, and who were referred to cancer centers in a large, representative Canadian province were reviewed. Baseline patient characteristics, including common comorbidities, were compared between men and women. Multivariable analysis was used to evaluate the associations between sex and survival outcomes.

RESULTS: We identified 1837 patients. Median age was 69 (interquartile range 60-76) years, and there were 867 women (47%) and 970 men (53%). Men were more likely to report ischemic heart disease, diabetes, dyslipidemia, and obesity (all P < .001). On multivariable analysis, men had worse overall and recurrence-free survival compared to women (hazard ratio [HR] = 1.38, 95% confidence interval [CI] 1.15-1.64; and HR = 1.40, 95% CI, 1.18-1.67, respectively). However, CRC-specific outcomes, including CRC-specific survival and time to recurrence, did not differ significantly between men and women (HR = 1.15, 95% CI, 0.91-1.45; and HR = 1.12, 95% CI, 0.90-1.40, respectively).

CONCLUSION: Women diagnosed with early stage CRC lived longer and had better general health than men. When noncancer causes of death were excluded, however, the trajectory of CRC appeared similar irrespective of sex. Early identification and better management of comorbidities may narrow the survival gap between men and women.